The present invention relates generally to a skewed-roller brake assembly and more specifically to a skewed-roller brake assembly with reduced package volume for use in applications with constrained packaging requirements.
Aircraft commonly utilize mechanical and control features that are critical to proper operation. Although it is preferable for all mechanical operations on an aircraft to function as designed without flaw, it is equally preferable to design such systems to adequately function upon failure of a single component. Such is the case when motors are utilized to move a load during operation. If a motor system becomes accidentally disconnected from a drive shaft it is often critical that the drive shaft is prevented from free-rotation to prevent uncontrolled movement of the load.
Such is the case with the drive system for aircraft flaps. Aircraft flaps are commonly driven by one or more mechanical actuators. The actuators, in turn, are commonly driven by a motor system. Failure of the motor system or transfer torque tubes can leave the aircraft flaps subject to acting air loads without adequate system restraint. Since allowing the aircraft flaps to be moved at the mercy of acting air loads is not desirable, it is common practice to incorporate safety brakes into the flap drive system. These safety brakes, or xe2x80x9cno-backxe2x80x9d brakes, prevent movement of the flaps upon accidental disengagement or failure of their driving motor system.
One known category of no-back brakes utilized for these type of applications is known as skewed-roller no-backs. Skewed roller-brakes utilize roller bearings contained within a cage assembly and positioned between rotor and stator discs. The axis of rotation of the rollers are skewed relative to a radial line from the rotational axis of the rotor and stator such that when compressed between the rotor and stator disc they provide sliding frictional resistance parallel to the rotational movement of the two discs. This allows the skewed-rollers to provide braking to the drive assembly through the application of frictional torque to the rotors.
Although skewed-roller brake assemblies are known in the prior art, they carry with them packaging considerations that limit their application in certain mechanisms. The packaging requirements necessary to fit the roller bearings and cage assemblies into the braking system can make the location of such systems difficult in areas constrained by available envelope.
It would, therefore, be highly desirable to have a skewed-roller brake assembly with improved packaging considerations such that the brake assembly could be incorporated into applications with severely constrained envelopes. It would further be highly desirable to have a braking system that could facilitate reductions in weight and cost of existing skewed-roller braking systems.
It is therefore an object to the present invention to provide a skewed-roller brake assembly with reduced profile for use in applications with constrained packaging requirements.
In accordance with the objects of the present invention a skewed-roller brake assembly is provided. The skewed-roller brake assembly includes a first rotor disc and a second rotor disc. A stator disc, positioned between the first and second rotor discs, includes a plurality of skewed-roller slots formed through the stator disc. A pair of roller elements are positioned within each of the plurality of skewed-roller slots such that a first of said pair of roller elements protrudes from the stator disc in the direction of the first rotor disc and a second of said pair of roller elements protrudes from the stator disc in the direction of the second rotor disc. When the first and second rotor discs are moved towards the stator disc, the first of said pair of roller elements and the second of said pair of roller elements rotate in concert while transmitting frictional torque to the first rotor disc and the second rotor disc respectively.